1 // SPDX-License-Identifier: GPL-2.0-only
3  * SPI controller driver for the Mikrotik RB4xx boards
16 #include <linux/spi/spi.h>
18 #include <asm/mach-ath79/ar71xx_regs.h>
27 	return __raw_readl(rbspi->base + reg);  in rb4xx_read()
32 	__raw_writel(value, rbspi->base + reg);  in rb4xx_write()
51 	for (i = 7; i >= 0; i--)  in do_spi_byte()
80 static void rb4xx_set_cs(struct spi_device *spi, bool enable)  in rb4xx_set_cs()  argument
82 	struct rb4xx_spi *rbspi = spi_master_get_devdata(spi->master);  in rb4xx_set_cs()
95 			      struct spi_device *spi, struct spi_transfer *t)  in rb4xx_transfer_one()  argument
104 	 * Prime the SPI register with the SPI device selected. The m25p80 boot  in rb4xx_transfer_one()
109 	if (spi->chip_select == 2)  in rb4xx_transfer_one()
116 	tx_buf = t->tx_buf;  in rb4xx_transfer_one()
117 	rx_buf = t->rx_buf;  in rb4xx_transfer_one()
118 	for (i = 0; i < t->len; ++i) {  in rb4xx_transfer_one()
119 		if (t->tx_nbits == SPI_NBITS_DUAL)  in rb4xx_transfer_one()
120 			/* CPLD can use two-wire transfers */  in rb4xx_transfer_one()
145 	master = spi_alloc_master(&pdev->dev, sizeof(*rbspi));  in rb4xx_spi_probe()
147 		return -ENOMEM;  in rb4xx_spi_probe()
149 	ahb_clk = devm_clk_get(&pdev->dev, "ahb");  in rb4xx_spi_probe()
153 	master->bus_num = 0;  in rb4xx_spi_probe()
154 	master->num_chipselect = 3;  in rb4xx_spi_probe()
155 	master->mode_bits = SPI_TX_DUAL;  in rb4xx_spi_probe()
156 	master->bits_per_word_mask = SPI_BPW_MASK(8);  in rb4xx_spi_probe()
157 	master->flags = SPI_MASTER_MUST_TX;  in rb4xx_spi_probe()
158 	master->transfer_one = rb4xx_transfer_one;  in rb4xx_spi_probe()
159 	master->set_cs = rb4xx_set_cs;  in rb4xx_spi_probe()
161 	err = devm_spi_register_master(&pdev->dev, master);  in rb4xx_spi_probe()
163 		dev_err(&pdev->dev, "failed to register SPI master\n");  in rb4xx_spi_probe()
172 	rbspi->base = spi_base;  in rb4xx_spi_probe()
173 	rbspi->clk = ahb_clk;  in rb4xx_spi_probe()
176 	/* Enable SPI */  in rb4xx_spi_probe()
186 	clk_disable_unprepare(rbspi->clk);  in rb4xx_spi_remove()
195 		.name = "rb4xx-spi",
201 MODULE_DESCRIPTION("Mikrotik RB4xx SPI controller driver");